Question 376188
You need to complete the square in x and y.
{{{5x^2+5y^2+60x+40y+215=0}}}
{{{x^2+12x+y^2+8y+43=0}}}
{{{(x^2+12x+36)+(y^2+8y+16)+43=36+16}}}
{{{(x+6)^2+(y+4)^2=52-16}}}
{{{highlight((x+6)^2+(y+4)^2=36)}}}